Effect of diatom abundance and biogenic silica availability on the population growth of tintinnid ciliates at Suruga Bay
Effect of diatom abundance and biogenic silica availability on the population growth of tintinnid ciliates at Suruga Bay
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DOI：
10.1007/s10872-020-00569-z
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发表时间：
2020-10
影响因子：
2.3
通讯作者：
Nhan Van Dinh;B. Casareto;Mohan P. Niraula;Keita Toyoda;Aussanee Meekaew;Yoshimi Suzuki
中科院分区：
文献类型：
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作者：
Nhan Van Dinh;B. Casareto;Mohan P. Niraula;Keita Toyoda;Aussanee Meekaew;Yoshimi Suzuki
2018年4月和11月，使用日本骏河湾次表层沃茨（10 m深）的孵化器，研究了硅藻丰度和生物硅（BSi）沉积对纤毛虫种群增长的影响。使用200 µm筛网预过滤用于孵育的海水，以去除中型浮游动物食草动物。溶解无机氮的初始浓度在两个季节相似，但磷酸盐和磷酸盐在4月高于11月。这使我们能够观察到不同的草酸供应量下的生长，并探讨BSi积累和食物供应量对tintinnids的生长的影响。浮游植物水华硅藻占主导地位的形成，4月和11月的孵化，但他们的生物量在4月高于11月，表现出营养物质的影响，特别是海藻酸，硅藻的生长。BSi浓度增加，在两个孵化，但在4月高于11月，证实硅藻丰度和大小对BSi沉积的影响。在两种培养条件下，锡虫生物量也有所增加，但4月份高于11月份，表明锡虫生物量受BSi浓度的影响。硅藻的种类组成通过为构建洛里卡提供选择性的物质而影响了锡壳类的种类组成。此外，研究结果还表明，在自然生态系统中，微纳米鞭毛虫通过微生物环和碎屑提供的食物供应可能限制了锡壳体的种群增长，这表明锡壳体在微生物环中是顶级捕食者
The effects of diatom abundance and biogenic silica (BSi) deposition on the population growth of tintinnid ciliates were investigated using incubations of sub-surface waters (10 m depth) of Suruga Bay, Japan in April and November 2018. Seawater for incubation was pre-filtered using a 200-µm mesh to remove mesozooplankton grazers. Initial concentrations of dissolved inorganic nitrogen were similar in both seasons, but silicic acid and phosphate were higher in April than in November. This allowed us to observe the growth of planktonic communities under varied silicic acid availability and explore the effects of BSi accumulation and food availability on the growth of tintinnids. Phytoplankton blooms dominated by diatoms formed in both, April and November incubations, but their biomass was higher in April than in November, demonstrating the effects of nutrients, particularly silicic acid, on diatom growth. The BSi concentration increased in both incubations but was higher in April than in November, confirming the effects of diatom abundance and size on BSi deposition. Tintinnid biomass also increased in both incubations but was higher in April than in November, showing that the biomass of tintinnid was affected by the BSi concentration. Species composition of diatoms affected the species composition of tintinnids by providing selected material for the construction of their lorica. Moreover, the results showed that the food supply mainly provided by pico-nanoflagellates via microbial loop and detritus may limit tintinnids’ population growth in natural planktonic ecosystems and this demonstrates tintinnids’ role as top predators in the microbial loop